Research for Terahertz Quantum Cascade Lasers using Nitride-based Semiconductors

太赫兹量子级联激光器(THz-QCL)是一种小尺寸、窄线宽、连续、高功率的太赫兹激光光源，具有广泛的应用前景。我们采用纵向光学声子去布居的方法发展了GaN/InAlGaN THz-QCL，以获得未发展的频率，即5-12 THz。首次用电流注入的方法观察到了氮化氮基GaN/AlGaN半导体超晶格(SLS)亚带间能级的自发辐射。我们利用QCL结构发射的偏振相关性，证实了THz自发辐射的起源。

Terahertz quantum-cascade lasers(THz-QCLs) are small-size, narrow line-width, cw and high-power THz laser light sources and are attractive for a lot of applications. We have developed GaN/InAlGaN THz-QCLs by employing a longitudinal-optical(LO) phonon depopulation scheme, for the purpose of achieving undeveloped frequencies, i. e., 5-12 THz. We achieved first observation of spontaneous emission from nitride-based GaN/AlGaN semiconductor superlattices(SLs) intersubband levels by current injection. We confirmed the origin of the THz spontaneous emission by using polarization dependence of emission from the QCL structures.